Process for the production of organic compounds containing nitrogen and chlorine combined in an-n=ccl-radical



United States Patent PROCESS FOR THE PRODUCTION OF ORGANIC COMPOUNDS CONTAINING NITROGEN AND ggLORINE COMBINED IN AN -N=CCl- RADI- Hans Holtschmidt and Wilfried Zecher, Cologne-Stemmheim, Germany, assignors toFarbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Original application Aug. 28, 1962, Ser. No. 220,070. Divided and this application Apr. 7, 1965, Ser. No. 446,394

2 C (Cl. 204-158) in which R and R separately stand for an alkyl or aryl group which may be substituted by halogen, cyano, aryl, alkyl, amino or imino groups, and in which R and R together with =N-- jointly stand for an isocyclic or heterocyclic ring, and in which X stands for an acyl group, with chlorine at temperatures below 140 C. to the extent that all replaceable hydrogen atoms are replaced by chlorine atoms,

and then (2) treating the chlorination product thus obtained with chlorine attemperatures between 140 and 300 C., whereby an acyl chloride is split 011.

It has been found that organic nitrogen compounds which contain the -N=CC1 radical can be obtained by (1) reacting an amine having the formula:

N-IB.

in which R and R separately stand for an alkyl or aryl group which may be substituted by halogen, cyano, aryl, alkyl, amino or imino groups, and in which R and R together with -=N jointly stand for an isocyclic or heterocyclic ring and in which 7 R stands for a methyl or an aryl group which can be further substituted, with chlorine at temperatures below 140 C; to the extent that all replaceable hydrogen atoms are replaced by chlorine atoms,

and then (2) treating the chlorination product thus obtained with chlorine at temperatures between 140 and 300 0., whereby an alkyl chloride is split oif.

It is important to conduct the reaction with the temperature so controlled that the amino compounds are so completely saturated with chlorine at temperatures below 140 C. that in the subsequent chlorinating dissociation, which takes place between 140 and 300 C., condensation and polymerization reactions are prevented. Furthermore, when chlorine is introduced at lower temperatures carbon atoms which are in the alpha position with 3,251,761 Patented May 17, 1966 reference to nitrogen acquire a positive charge which favors subsequent dissociation rather than any side reaction.

The amines mentioned are, in general, such strong bases that their hydrochlorides precipitate at the beginning of chlorination. Therefore, hydrochlorides or alkylation products (with alkyl halogenide) of these amines may be introduced from the very beginning. As chlorination proceeds the basicity of the amines is lowered to such a degree that the ammonium compound becomes unstable and hydrogen chloride or the chlorinated alkyl group is split ofi again. If the reaction is interrupted at this stage the chlorinated amines may be distilled off and thus separated. With aryl substituted amines it is pos-- lA dimethyl-piperaziue l,4-bis( 2-ehloroethyl)- N-met yl-plperazine plperazine C H: 0 Ha NEG -C Hz-N N C -C Na-C H2N CH CH3 N,N-dimethylaminoacetonitrile N,N-dimethylaminopropiononitrile 0 Ha H3 C1C H2C Hz-N H01 0 HsN 1101 0 H 0 Ha C Hz-N NC Ha C 1' C Ha H:

N C H 2 I 02H H20 N\ C H N I on, 011,, 2 5

hexamethylene tetramine C Ha N\ CH C l 3 -N=C N C Ha N HI 0 H3 0 Ha CH: CH

/CH /CHa N -N\ CH CH3 N /CH CliHg N (1113 01 |N\ I I f TN N N CH: CHa N N 3H:

CH3 Cl- CClaN=C CH3 In addition to a substantial chlorination of the whole molecule there may be consequential reactions with which this invention is also concerned. Ring structures, for ex-.

ample, N,N'-dimethyl piperazine, are stabilized by a transformation to the aromatic state; Urotropin(hexamethylene tetramine) is split during chlorination in such a manner that cyanuric chloride is obtained as a reaction product. In the case of dimethylamino acetonitrile the cyano radical is split off and the molecule becomes dimerlc.

Chlorination can also be carried out in a solvent, especially if ammonium salts with high melting points are used as starting materials. Suitable solvents are, for example, 1,2,4-trichlorobenzene, chloroform, tetrachloroethane and phthalyl chloride.-

The invention is the more surprising in that direct chlorination of aliphatic or aliphatic-aromatic amines or of their salts have hitherto been described in few cases. It is,-f0r example, known that the addition product of chlorine and trimethyl amine sometimes dissociates explosively at 35 C. (see Houben-Weyl, Methoden der organischen Chemie, vol. V/3, page 642).

Some of the products obtainable according to the process of the present invention are known. The known compounds are, however, only obtainable with difficulty, by other methods. They are valuable products for the prep aration of pest control agents, herbicides, dyestuffs and plastics. Further, they can assuch be used as insecticides and nematocides, because of their high activity against spiders, mites, flies and fungi.

As a typical example of the high nematocidal activity of the products of the present invention the treatment of infested soil with 2,4,6-trichlorophenyl-imidocarbonyl chlordie is shown below.

Soil is heavily infested with the root cyst nematode Meloidogyne incognita. 25, 50, 100 and 200 p.p.m. of 2,4,6-trichlorophenyl-imidocarbonyl chloride are added to one liter of infested soil. The active agent is applied in admixture with talcum, this mixture containing 1% of active ingredient.

One week after the preparation, seed of soft lettuce was put into the soil. After a 4 weeks period the plants were checked for cyst formation. The following table shows the efl ectiveness of the compound in preventing cyst formation.

Percent 25 p.p.m. 90 50 p.p.m. 100 100 p.p.m.; 100 200 p.p.m. i 100 The following examples are given for the purpose of illustrating the present invention:

EXAMPLE 1 116 parts by weight of 1,2-bis(dimethy1arnino)ethane are dissolved in 1000 parts by volume of 1,2,4-trichloro benzene. A weak current of chlorine is then introduced and the strongly exothermic reaction is restrained by cooling so that the temperature remains between 7080 C. When the exothermic reaction has subsided, chlorination is continued while the mixture is irradiated with ultra violet light, and the temperature rise is controlled in such a way that within one hour a rise of 10-15 C. takes place. Subsequently chlorination is continued for a further 3 hours at 200-230 C., then nitrogen is blown through and the solution left to cool. On cooling, most of the ethylene-1,2-bis(imidocarbonylchloride) precipitates as crystals, the remainder being obtained by further evaporating the solution.

Melting point (toluene) 166 C. (white flakes).

Analysis.-C Cl N found: C, 13.56%; N, 7.90%; Cl, 79.05%. Calculated: C, 13.3%; N, 7.8%; Cl, 79.0%.

Determination of molecular weight (after period in hexach1oro-benzene)-found: 365. Calculated: 360.

The same compound can be obtained by chlorinating dimethylamino-acetonitrile NC-CHz-N CHa with dissociation of cyanogen chloride by chlorinating under the same conditions as described hereinbefore in this example.

EXAMPLE 2 140 parts by weight of hexamethylene-tetramine are suspended in 600 cc. of tetrachloroethane and a gentle stream of chlorine is passed therethrough at room temperature, whereby the temperature quickly rises to -90" C. and the suspension changes to a thick paste. Subsequently the temperature is slowly raised to 1315-140 C. (10 degrees per hour). Chlorination is continued while the mixture is irradiated with the ultra violet light until most of the substance has dissolved and there is only a small residue left. tetrachloroethane is distilled off and the remaining yellow oil is further chlorinated at 200-240 C. During chlorination large quantities of a White substance of boiling point 190 C. and melting point 146 C. sublime in the condenser. The same substance is obtained by the subsequent distillation of the chlorination product. The substance was identified by analysis, mixed melting point and spectrum as cyanuric chloride.

EXAMPLE 3 GlaC-N=C 355 parts by weight (6 mols) of trimethylamine are dissolved in 1000 parts by volume of 1,2,4.-trich1orobenzene while the solution is cooled with ice. Undercontinned cooling hydrogen chloride is introduced to saturatron point. A pasty suspension of the hydrochloride in trichlorobenzene is obtained, into which chlorine is introduced at 140 C. for 20 hours while stirring and irradiating the mixture with ultra violet light.

The reaction product, a clear dark brown solution, is fractionated in vacuum through a silvered column. The solvent, boiling point -95 C. at 16 mm. Hg is separated from the other fractions, boiling point 60-90 C. at 16 mm. Hg and 210 C., and a mixture of chlorinated amines is thus obtained which is chlorinated for 4 hours at C. and for 11 hours at 200 C., while the mixture is irradiated with ultra violet light. The product is again After filtering off the residue the Chlorine is passed into a suspension'of 576 grams (4 mols) of finely ground 1-dimethylamin02-chl0roethane hydrochloride in'700 cc. of 1,2,4-trichlorobenzene while.

stirring and irradiating the mixture with ultra violet light. After about 40 hours at 130-140 C. the salt has dissolved with liberation of hydrogen chloride. The brown reaction liquid is further chlorinated for 3 hours at 160 C. and for 16 hours at 210 C. The chloroform liberated during the reaction may be separated with a conventional water trap. After removing hydrogen chloride and excess chlorine by means of nitrogen the reaction mixture is fractionated in vacuum over a silvered column. At boiling point 120121 C. and 13 mm. Hg pentachloroethylimidocarbonyl chloride distils over as a colorless liquid.

Analysis.C Cl N (molecular weight: 29-8.24) calcu- Found: C, 30.04%, 30.36%; H, 0.76%, 0.89%;N, 5.23%, 5.25%; Cl, 64.4%, 64.5%.

EXAMPLE 5 Trichlorophenylimidocarbonyl chloride 400 grams (2.33 mols) of N-phenyl-N,N,N-trimethylammonium chloride are suspended in 700 cc. of 1,2,4- trichlorobenzene. The mixture is then chlorinated for 13 hours at 100 C. while stirring and irradiating it with an ultraviolet lamp. The ammonium salt dissolves and, with liberation of hydrogen chloride, a yellow and a dark brown liquid are obtained which remainseparated in two phases. While continuing the introduction of chlorine the temperature is raised by 20 C. every two hours until 200 C. has been reached, when chlorination is continued for a further 7 hours at this temperature. The reaction mixture is fractionated in vacuum, the solvent is separated and the residue chlorinated again at 240 C. for 18 hours. The reaction product is then fractionated through a silvered column. The trichloro-phenyl-imidocarbonyl chloride distils over as a faintly yellow liquid with a boiling point of 148153 C. at 15 mm. Hg.

Analysis.C-;H C1 N (molecular weight: 277.4)- --calculated: C, 30.32%; H, 0.73%; N, 5.05%; Cl, 63.91%. Found: C, 30.04%, 30.36%; H, 0.76%, 0.89%; N, 5.23%, 5.25%; Cl, 64.4%, 64.5

EXAMPLE 6 2,3,5,6-tetrachloro-pyrazine from 1,4-dimethyl-piperazine fraction from which 2,3,5,6-tetrachloropyrazine precipi tates, on cooling, as colorless crystals. After re-crystallization from methanol colorless flakes of melting point 97-99 C. are obtained.

Analysis.-C Cl N (molecular weight: 217 .9)--calculated: C, 22.05%; Cl, 65.09%. Found: C, 22.41%, 22.34%; Cl, 64.7, 65.0%.

6 EXAMPLE 7 2,3,5,6-tetrachl0r0-pyrazine from 1,4-bis-(2-hydr0xyethyl)-piperazine pyrazine crystallizes on cooling. Recrystallization from acetonitrile or methanol yields colorless flakes of melting point 9699' C.

Analysis.C Cl N (molecular weight: 217.9)-calculated: C, 22.05%; N, 12.86%. Found: C, 22.40%, 22.42%; N, 12.65%, 12.66%.

EXAMPLE 8 T etrachloropyridines and pentachloro-pyridine from N- methyl-piperidine Chlorine is passed at 10 C. into a solution of 198 grams (2 mols) of N-methyl-piperidine in 200 cc. of chloroform. while cooling with ice. A pasty suspension is obtained which is then chlorinated at 20 C., while the mixture is stirred and irradiated with ultraviolet light, until the solution becomes clear. The temperature is then slowly raised, the chloroform distilled off at 60 C., and while chlorine is passed under further irradiation with ultraviolet light the mixture is maintained for several hours each at C., C.,- C., C. and finally at 200 C. Subsequently nitrogen is blown through the mixture and it is fractionated in vacuum. At boiling point l09l25 C. at a pressure of 12 mm. Hg, 234 grams tetrachloropyridine distils over. A fraction of boiling point l25l40 C. at a pressure of 12 mm. Hg, yields when cooled a solid precipitate of 31 grams (=6.2% of the theoretical) of pentachloropyridine (from ethanol, colorless polyhedrons having a melting point of 125127 C.) and a mother liquor containing 22 grams of tetrachloropyridine. The: total yield of isomeric tetrachloropyridines amounts to 256 grams (59% of the theoretical).

Analysis.C Cl N (molecular weight: 251.4)-calc'ulated: C, 23.89%; Cl, 70.52%; N, 5.57%. 24.04%, 24.20%; Cl, 70.45%, 70.65%; N, 5.71%, 5.76%.

Analysis.-C HCl N (molecular weight: 216.9)-calculated: C, 27.69%; H, 0.47%; N, 6.46%. Found: C, 27.20%, 27.46%; H, 0.5%, 0.5%; N, 6.41%, 6.41%.

EXAMPLE 9 366 parts by weight of dimethyl-aniline are chlorinated, first without iradiation, at a temperature between 20-60 C. until the reaction stops being exothermic (chlorination of the nucleus). From a temperature of 60 C. onwards, the chlorination is then continued under ultraviolet irradiation. The temperature is raised in such a way that a temperature rise of about 10 C. per hour takes place. When the temperature has reached -220 C., chlorination is continued for a further 3 hours at this temperature. Nitrogen is then passed through in order to remove any dissolved chlorine.

During the subsequent vacuum-distillation trichlorophenylimidocarbonyl chloride distils over at a pressure of 0.3 mm. Hg at 889l C.

Yield: 648 parts by weight, n =1.597'0.

Analysis.-C H NC1 calculated: C, 30.15%; H, 0.72%; N, 5.06%; Cl, 64.2%. Found: C, 30.17%; H, 0.78%; N, 5.65%; C1, 64.4%.

EXAMPLE 10 816 parts by weight of 2-diemthylamino-4,6-dichlorotriazine are melted at 125 C. and chlorine is introduced into the melt at a temperature of l 30l50 C.

Found: C,

After about 4 hour when the exothermic reaction has subsided, the chlorination is continued under ultraviolet irradiation and the temperature raised by 10 C. per hour until it reaches 220 C. At this temperature chlorine is introduced, while the mixture is irradiated for about 8 hours. The product is then fractionated under a water-jet vacuum. After first runnings consisting of Yieldz 672 parts by weight, n z 1.5751.

Analysis.C N Cl -calculated: C. 19.5%; N, 22.8%; Cl, 57.6%. Found: C, 19.62%; N, 22.87% Cl, 56.97%.

The product is identical with the so-called tetrameric cyanogen chloride which is formed in small quantities in the trimerization of cyanogen chloride into cyanuric chloride.

EXAMPLE 11 110 parts by weight of 2,4-bis(d.imethylamine)-6- chlorotriazine-1,3,5 are chlorinated as describedin Example 10. Upon fractionating, there are obtained, after first runnings of cyanuric chloride and trichloromethylimidocarbonyl chloride 59 parts by weight of the compound B.P. 106-ll2 C./0.07 mm. Hg; 11 1.5854.

Analysis.-C N Cl calculatedz C, 19.6%; N, 22.8%; CI, 57.9%. Found: C, 19.94%; N, 22.57%; Cl, 58.45%.

EXAMPLE 12 A mixture of 385 parts by weight of N,N-dimethylpentachloroaniline and 250 parts by volume of chloroform is chlorinated at 4055 C. while irradiating it with ultraviolet light, the mixture being cooled with icewater because of the strongly exothermic reaction. The temperature of the reaction mixture is then slowly raised, as described in Example 9 and during which period the chloroform distils off, finally the mixture is kept for 8 hours at ZOO-230 C. Excess chlorine is then re moved by blowing through nitrogen and pentachlorophenylimido carbonyl chloride having the foregoing formula is distilled off under high vacuum. It boils at a pressure of 0.1 mm. Hg. at 134-138 C. and has a refractive index n =1.6258.

Analysis.C Cl N-calculated: C, 24.3%; N. 4.05%; Cl, 70.6%. Found: C, 24.4%; N, 4.5%; Cl, 71.5%;

EXAMPLE 13 I Cl r V t 8 t 232 grams of a compound having the formula Cl Cl that was obtained by condensation of trichlorophenylimidocarbonyl chloride (Example 5) and dimethylamine [B.P. 128-131 C./0.09 mm. Hg] are chlorinated as described in Example 12. Excess chlorine is then removed by blowing through nitrogen and the reaction product distilled ofl? under a high vacuum.

Boiling point 1384427 C. at 0.1 mm. Hg; n =1.6080.

Analysis.C H Cl N calculated:. C, 28.3%; H, 0.59%; N, 8.25%; Cl, 63.0%. Found: C, 28.47%; H, 0.65%; N, 8.22%; Cl, 63.55%.

EXAMPLE 14 Cl Cl A mixture of 366 parts by weight of 2-N,N-dimethylamino-toluene and 300 parts by volume of chloroform is chlorinated as described in Example 12 and worked up. The reaction product boils at a pressure of 0.05 mm. Hg at 130l36-C.; n =1.6107.

Analysis.C H Cl Ncalculated: C, 29.4% 0.92%; N, 4.3%; Cl, 65.4%. Found: C, 28.96%; H, 0.91%; N, 4.28%; CI, 65.45%.

EXAMPLE l5 OCCl N Cl CH'LA,

240 parts by weight of 2,5-dimethylamino-3,6-dichlorop-benzoquinone and 1500 parts by volume of trichloro- C, 32.2%; N, Found: C, 32.7%; N,

Found To 397 parts by weight of N-methyl-pyrrolidone are added 500 parts by weight of 1,2,4-trichlorobenzene; the mixture is chlorinated at C. while the mixture is stirred and irradiated with ultraviolet light. After 16 hours the temperature is raised by 20 C. every 3 hours while chlorine is continually introduced and then the mixture kept at 220-230 C. for 20 hours. Hydrogen chloride and excess chlorine are then driven out with nitrogen and the reaction mixture is subjetced to frac- Without external supply of heat the i tional distillation in a silver-lined column. 3-ch1oroformylhexachloropropylimidocarbonyl chloride distils over at a pressure of 15 mm. Hg at 188189 C. and forms a crystalline solid in the receiver. By recrystallization from acetonitrile the product is obtained in the form of colorless polyhedrons having a melting point of 98- 101 C.

Analysis.Molecular weight 409.2. Calculated for C C1 NO: C, 14.68%; Cl, 77.99%; N, 3.42%; O, 3.91%. Found: C, 14.84%, 14.86%; Cl, 77.75%, 77.90%; N, 3.63%, 3.63%; 0, 4.11%, 4.31%.

We claim:

1. A process for the production of an organic compound containing chlorine and nitrogen combined in the -N=CClradical which comprises:

(A) reacting an amino compound selected from the group consisting of (i) amines of the formula N-Rs wherein R and R taken together with the nitrogen to which each is attached stand for a heterocyclic radical of the group consisting of five and six membered heterocyclic radicals containing at least'three nitrogen atoms wherein nitrogen is the only heterocyclic atom,

R when taken alone stands for a radical selected from the group consisting of lower alkyl, chloro-substituted lower alkyl, cyano-substituted lower alkyl, phenyl-substituted lower alkyl, phenyl, chloro-phenyl, cyano-phenyl, nitrophenyl, naphthyl, benzoquinonyl, chloro-substituted triazinyl, chloro and amino-substituted triazinyl,

wherein R is a member selected from the group consisting of chloro-phenyl, lower chloro alkyl and phenyl, and R stands for a member selected from the group consisting of chloro and amino, and

R1 R4N wherein R is lower alkyl and R and R are separately lower alkyl and chlorine at a higher temperature between 140 and 300 C. while it is irradiated with ultraviolet light, and (C) recovering the resulting organic compound containing nitrogen and chlorine combined in an --N=CC1 radical. 2. A process for the production of an organic nitrogen compound containing chlorine and nitrogen combined in the -N=CC1 radical which comprises (A) reacting a compound selected from the group consisting of (i) amines of the formula N-Rs v in which R and R together with =N- jointly stand for ring selected from the group consisting of five and six membered heterocyclic rings containing at least three nitrogen atoms wherein nitrogen is the only heteroatom, and in which R stands for a member selected from the group consisting of alkyl and aryl radicals and their halogen, cyano, aryl, alkyl, amino and imino derivatives, (ii) salts of said amines with hydrogen halides and (iii) quaternary salts of said amines with hydrogen halides with chlorine at temperatures below C. until all replaceable hydrogen atoms are replaced by chloro-atoms,

(B) treating the chlorination product thus obtained with chlorine at temperatures between 140 and 300 C., whereby alkyl chloride is split oil, and

(C) recovering the organic nitrogen compound from the reaction mixture.

No references cited.

WALTER A. MODANCE, Primary Examiner. 

1. A PROCESS FOR THE PRODUCTION OF AN ORGANIC COMPOUND CONTAINING CHLORINE AND NITROGEN COMBINED IN THE -N=CCL- RADICAL WHICH COMPRISES: (A) REACTING AN AMINO COMPOUND SELECTED FROM THE GROUP CONSISTING OF (I) AMINES OF THE FORMULA
 2. A PROCESS FOR THE PRODUCTION OF AN ORGANIC NITROGEN COMPOUND CONTAINING CHLORINE AND NITROGEN COMBINED IN THE -N=CCL- RADICAL WHICH COMPRISES (A) REACTING A COMPOUND SELECTED FROM THE GROUP CONSISTING OF (I) AMINES OF THE FORMULA 